The present invention relates to a waterproofed vapor-permeable sole for shoes.
It is known that the main problem noted when using shoes provided with an ordinary sole made of natural material such as leather or the like is constituted by wet environments.
When rain and bad weather cause the streets to be wet and slippery, it is in fact not advisable to use shoes with a leather sole, since leather, indeed because of its characteristic of being vapor-permeable and healthy for the foot, is not impermeable but indeed absorbs water.
The thinner the leather, the faster it becomes impregnated with water or moisture until it wets the user's foot.
Another drawback is that the leather tread is not patterned but is smooth or sometimes even polished with waxes.
This is a further problem in wet environments, since grip is unsteady in such conditions.
Accordingly, the use of soles with a leather tread is constrained by weather conditions, and therefore shoes having this type of material are mainly provided in summer collections by shoe manufacturers.
An attempt to obviate this drawback has been made by inserting between the leather tread and the foot resting region an element made of polyurethane or PVC, which element however inhibits vapor permeation and relegates the use of leather to a purely aesthetic matter.
A sole, disclosed in EP-0 619 959 by the same Applicant, has also been devised which comprises a tread made of leather or similar material which is at least partially covered, in an upward region, by a membrane made of a material which is permeable to vapor and impermeable to water.
The thread is then assembled at least peripherally with at least one upper part made of rubber or similar material which has a plurality of through holes at least in the regions affected by the membrane.
Although it is a considerable technical step forward, since the leather tread is waterproofed, such sole has drawbacks, the main one being the very nature of leather, which is a vapor-permeable material, as mentioned, but whose perspiration degree is not high enough to rapidly dissipate all the heat and vapor that form during use inside the shoe.